Purpose: :
Leigh syndrome is an inherited progressive neurometabolic disorder that affects the central nervous system with a typical onset in infancy or early childhood. The major clinical features are failure to thrive, hypotonus, psychomotor regression, brain stem dysfunction, ataxia, and dystonia. The condition can be caused by several different gene mutations in mitochondrial or nuclear DNA. The aim of this study was to determine visual and ocular findings in children with Leigh Syndrome.

Methods: :
A retrospective study was performed on 31 children with Leigh syndrome (16 female) with a mean age of 3.2 years (range 0.7-9.5) investigated and diagnosed by a multidisciplinary team at the Queen Silvia Children’s Hospital in Gothenburg, Sweden, during 1987-2009. Most of the children were Swedish (n=22), the others originated from Norway (n=4), Iceland (n=1), Bosnia (n=1), Turkey (n=2), and Lebanon (n=1). 13 had known genetic mutations. The children had undergone an ophthalmological examination, including visual acuity (VA), eye motility, refraction, slit-lamp examination, ophthalmoscopy and, in almost half of the cases, a full-field electroretinogram (ERG).

Results: :
27/31(87%) of the children had one or more ophthalmological finding such as low VA (n=13/17), myopia (≥0.5 dioptre (D) S.E. (spherical equivalent)) (n=1/13), hyperopia (≥2.0 D S.E.) (n=6/13), astigmatism (≥1.0 D) (n=9/13), ptosis (n=2/30), reduced eye motility (n=4/29), strabismus (n=6/30), nystagmus (n=6/30), photophobia (n=3/5), optic atrophy (n=11/29), and pigmentation in macula/periphery (n=4/28). 10/15 investigated children with full-field ERG were found to be normal, two had a rod-cone dystrophy, one child had reduced rod amplitudes, another one had reduced cone amplitudes, and in one child both subnormal cone and rod amplitudes were found. 2/3 children with photophobia had reduced cone and rod responses on full-field ERG.

Conclusions: :
In this unique cohort of children with Leigh syndrome, a vast majority showed ophthalmological findings at the time of the investigation. Low VA was common and more than 1/3 of the children had optic atrophy, with or without a combination of photophobia and nystagmus. Many of the children were hyperopastigmatic. Therefore, we recommend that an ophthalmological examination, including ERG, be performed on all patients who are suspected to have this disorder.